Holocene Natural History in the Nara Basin．III

Nara Basin is the birth place of the first unified Japanese state.There was the oldest cultivated area and settled the first capital in seven century． We intend to reveal its post glacial natural history through the sediment deposited in the basin with archaeologic， geologic and paleontologic techniques． In the last three years we obtained twenty geologic columnar samples from the basin.They attain totally to about 100 meters．First we described their lithologic features and determined their chronologic units with excavated stone implements，volcanic ashes intercalated，14C ages mainly measured on peat and micropaleontologic criteria． Now we can explain a part of the natural history between 34,000 and 20,000 years ago.At that time the forest surrounding the basin were occupied microtherm plant such as Abies，Picea， Pinus (Haploxylon)，Tsuga, Betula，Fagus，and Quercus (Lepidobalanus). In the plain of the basin swamps and bogs developed here and there depositing fen peat and gowing aquatic plants. On the mound there developed grassland growing Percicaria，Gramineae，Cyperaceae，Compositae， Artemisia and Sanguisorba